Delfleet Evolution is a thick product, tough as nails and very suspectable to orange peel, as mentioned by "One More Time", proper gun adjustments can make a big difference, try 5% more reduction, both on your F3993 Primer and your paint...If I am correct, PPG Delfleet Tech sheets suggest using a viscosity cup for this reason and they also recommended for this product to be sprayed with a pressure pot. Using a pressure pot does make a difference with respect to flow.

If you look at factory finishes that have used Delfleet from the factory, they do have a certain amount of Orange Peel as does it's sister of a different mother, Dupont's Imrom.